1 /* 2 * linux/include/linux/jbd2.h 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com> 5 * 6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Definitions for transaction data structures for the buffer cache 13 * filesystem journaling support. 14 */ 15 16 #ifndef _LINUX_JBD2_H 17 #define _LINUX_JBD2_H 18 19 /* Allow this file to be included directly into e2fsprogs */ 20 #ifndef __KERNEL__ 21 #include "jfs_compat.h" 22 #define JBD2_DEBUG 23 #else 24 25 #include <linux/types.h> 26 #include <linux/buffer_head.h> 27 #include <linux/journal-head.h> 28 #include <linux/stddef.h> 29 #include <linux/bit_spinlock.h> 30 #include <linux/mutex.h> 31 #include <linux/timer.h> 32 #include <linux/slab.h> 33 #include <crypto/hash.h> 34 #endif 35 36 #define journal_oom_retry 1 37 38 /* 39 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds 40 * certain classes of error which can occur due to failed IOs. Under 41 * normal use we want ext4 to continue after such errors, because 42 * hardware _can_ fail, but for debugging purposes when running tests on 43 * known-good hardware we may want to trap these errors. 44 */ 45 #undef JBD2_PARANOID_IOFAIL 46 47 /* 48 * The default maximum commit age, in seconds. 49 */ 50 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5 51 52 #ifdef CONFIG_JBD2_DEBUG 53 /* 54 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal 55 * consistency checks. By default we don't do this unless 56 * CONFIG_JBD2_DEBUG is on. 57 */ 58 #define JBD2_EXPENSIVE_CHECKING 59 extern ushort jbd2_journal_enable_debug; 60 61 #define jbd_debug(n, f, a...) \ 62 do { \ 63 if ((n) <= jbd2_journal_enable_debug) { \ 64 printk (KERN_DEBUG "(%s, %d): %s: ", \ 65 __FILE__, __LINE__, __func__); \ 66 printk (f, ## a); \ 67 } \ 68 } while (0) 69 #else 70 #define jbd_debug(f, a...) /**/ 71 #endif 72 73 extern void *jbd2_alloc(size_t size, gfp_t flags); 74 extern void jbd2_free(void *ptr, size_t size); 75 76 #define JBD2_MIN_JOURNAL_BLOCKS 1024 77 78 #ifdef __KERNEL__ 79 80 /** 81 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 82 * 83 * All filesystem modifications made by the process go 84 * through this handle. Recursive operations (such as quota operations) 85 * are gathered into a single update. 86 * 87 * The buffer credits field is used to account for journaled buffers 88 * being modified by the running process. To ensure that there is 89 * enough log space for all outstanding operations, we need to limit the 90 * number of outstanding buffers possible at any time. When the 91 * operation completes, any buffer credits not used are credited back to 92 * the transaction, so that at all times we know how many buffers the 93 * outstanding updates on a transaction might possibly touch. 94 * 95 * This is an opaque datatype. 96 **/ 97 typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */ 98 99 100 /** 101 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 102 * 103 * journal_t is linked to from the fs superblock structure. 104 * 105 * We use the journal_t to keep track of all outstanding transaction 106 * activity on the filesystem, and to manage the state of the log 107 * writing process. 108 * 109 * This is an opaque datatype. 110 **/ 111 typedef struct journal_s journal_t; /* Journal control structure */ 112 #endif 113 114 /* 115 * Internal structures used by the logging mechanism: 116 */ 117 118 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 119 120 /* 121 * On-disk structures 122 */ 123 124 /* 125 * Descriptor block types: 126 */ 127 128 #define JBD2_DESCRIPTOR_BLOCK 1 129 #define JBD2_COMMIT_BLOCK 2 130 #define JBD2_SUPERBLOCK_V1 3 131 #define JBD2_SUPERBLOCK_V2 4 132 #define JBD2_REVOKE_BLOCK 5 133 134 /* 135 * Standard header for all descriptor blocks: 136 */ 137 typedef struct journal_header_s 138 { 139 __be32 h_magic; 140 __be32 h_blocktype; 141 __be32 h_sequence; 142 } journal_header_t; 143 144 /* 145 * Checksum types. 146 */ 147 #define JBD2_CRC32_CHKSUM 1 148 #define JBD2_MD5_CHKSUM 2 149 #define JBD2_SHA1_CHKSUM 3 150 #define JBD2_CRC32C_CHKSUM 4 151 152 #define JBD2_CRC32_CHKSUM_SIZE 4 153 154 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) 155 /* 156 * Commit block header for storing transactional checksums: 157 * 158 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum* 159 * fields are used to store a checksum of the descriptor and data blocks. 160 * 161 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum 162 * field is used to store crc32c(uuid+commit_block). Each journal metadata 163 * block gets its own checksum, and data block checksums are stored in 164 * journal_block_tag (in the descriptor). The other h_chksum* fields are 165 * not used. 166 * 167 * Checksum v1 and v2 are mutually exclusive features. 168 */ 169 struct commit_header { 170 __be32 h_magic; 171 __be32 h_blocktype; 172 __be32 h_sequence; 173 unsigned char h_chksum_type; 174 unsigned char h_chksum_size; 175 unsigned char h_padding[2]; 176 __be32 h_chksum[JBD2_CHECKSUM_BYTES]; 177 __be64 h_commit_sec; 178 __be32 h_commit_nsec; 179 }; 180 181 /* 182 * The block tag: used to describe a single buffer in the journal. 183 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 184 * raw struct shouldn't be used for pointer math or sizeof() - use 185 * journal_tag_bytes(journal) instead to compute this. 186 */ 187 typedef struct journal_block_tag_s 188 { 189 __be32 t_blocknr; /* The on-disk block number */ 190 __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */ 191 __be16 t_flags; /* See below */ 192 __be32 t_blocknr_high; /* most-significant high 32bits. */ 193 } journal_block_tag_t; 194 195 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) 196 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) 197 198 /* Tail of descriptor block, for checksumming */ 199 struct jbd2_journal_block_tail { 200 __be32 t_checksum; /* crc32c(uuid+descr_block) */ 201 }; 202 203 /* 204 * The revoke descriptor: used on disk to describe a series of blocks to 205 * be revoked from the log 206 */ 207 typedef struct jbd2_journal_revoke_header_s 208 { 209 journal_header_t r_header; 210 __be32 r_count; /* Count of bytes used in the block */ 211 } jbd2_journal_revoke_header_t; 212 213 /* Tail of revoke block, for checksumming */ 214 struct jbd2_journal_revoke_tail { 215 __be32 r_checksum; /* crc32c(uuid+revoke_block) */ 216 }; 217 218 /* Definitions for the journal tag flags word: */ 219 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 220 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 221 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 222 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 223 224 225 /* 226 * The journal superblock. All fields are in big-endian byte order. 227 */ 228 typedef struct journal_superblock_s 229 { 230 /* 0x0000 */ 231 journal_header_t s_header; 232 233 /* 0x000C */ 234 /* Static information describing the journal */ 235 __be32 s_blocksize; /* journal device blocksize */ 236 __be32 s_maxlen; /* total blocks in journal file */ 237 __be32 s_first; /* first block of log information */ 238 239 /* 0x0018 */ 240 /* Dynamic information describing the current state of the log */ 241 __be32 s_sequence; /* first commit ID expected in log */ 242 __be32 s_start; /* blocknr of start of log */ 243 244 /* 0x0020 */ 245 /* Error value, as set by jbd2_journal_abort(). */ 246 __be32 s_errno; 247 248 /* 0x0024 */ 249 /* Remaining fields are only valid in a version-2 superblock */ 250 __be32 s_feature_compat; /* compatible feature set */ 251 __be32 s_feature_incompat; /* incompatible feature set */ 252 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 253 /* 0x0030 */ 254 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 255 256 /* 0x0040 */ 257 __be32 s_nr_users; /* Nr of filesystems sharing log */ 258 259 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 260 261 /* 0x0048 */ 262 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 263 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 264 265 /* 0x0050 */ 266 __u8 s_checksum_type; /* checksum type */ 267 __u8 s_padding2[3]; 268 __u32 s_padding[42]; 269 __be32 s_checksum; /* crc32c(superblock) */ 270 271 /* 0x0100 */ 272 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 273 /* 0x0400 */ 274 } journal_superblock_t; 275 276 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 277 ((j)->j_format_version >= 2 && \ 278 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 279 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 280 ((j)->j_format_version >= 2 && \ 281 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 282 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 283 ((j)->j_format_version >= 2 && \ 284 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 285 286 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001 287 288 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 289 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 290 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 291 #define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008 292 293 /* Features known to this kernel version: */ 294 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM 295 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 296 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 297 JBD2_FEATURE_INCOMPAT_64BIT | \ 298 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \ 299 JBD2_FEATURE_INCOMPAT_CSUM_V2) 300 301 #ifdef __KERNEL__ 302 303 #include <linux/fs.h> 304 #include <linux/sched.h> 305 #include <linux/jbd_common.h> 306 307 #define J_ASSERT(assert) BUG_ON(!(assert)) 308 309 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 310 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 311 312 #if defined(JBD2_PARANOID_IOFAIL) 313 #define J_EXPECT(expr, why...) J_ASSERT(expr) 314 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 315 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 316 #else 317 #define __journal_expect(expr, why...) \ 318 ({ \ 319 int val = (expr); \ 320 if (!val) { \ 321 printk(KERN_ERR \ 322 "JBD2 unexpected failure: %s: %s;\n", \ 323 __func__, #expr); \ 324 printk(KERN_ERR why "\n"); \ 325 } \ 326 val; \ 327 }) 328 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 329 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 330 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 331 #endif 332 333 /* Flags in jbd_inode->i_flags */ 334 #define __JI_COMMIT_RUNNING 0 335 /* Commit of the inode data in progress. We use this flag to protect us from 336 * concurrent deletion of inode. We cannot use reference to inode for this 337 * since we cannot afford doing last iput() on behalf of kjournald 338 */ 339 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) 340 341 /** 342 * struct jbd_inode is the structure linking inodes in ordered mode 343 * present in a transaction so that we can sync them during commit. 344 */ 345 struct jbd2_inode { 346 /* Which transaction does this inode belong to? Either the running 347 * transaction or the committing one. [j_list_lock] */ 348 transaction_t *i_transaction; 349 350 /* Pointer to the running transaction modifying inode's data in case 351 * there is already a committing transaction touching it. [j_list_lock] */ 352 transaction_t *i_next_transaction; 353 354 /* List of inodes in the i_transaction [j_list_lock] */ 355 struct list_head i_list; 356 357 /* VFS inode this inode belongs to [constant during the lifetime 358 * of the structure] */ 359 struct inode *i_vfs_inode; 360 361 /* Flags of inode [j_list_lock] */ 362 unsigned long i_flags; 363 }; 364 365 struct jbd2_revoke_table_s; 366 367 /** 368 * struct handle_s - The handle_s type is the concrete type associated with 369 * handle_t. 370 * @h_transaction: Which compound transaction is this update a part of? 371 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 372 * @h_ref: Reference count on this handle 373 * @h_err: Field for caller's use to track errors through large fs operations 374 * @h_sync: flag for sync-on-close 375 * @h_jdata: flag to force data journaling 376 * @h_aborted: flag indicating fatal error on handle 377 **/ 378 379 /* Docbook can't yet cope with the bit fields, but will leave the documentation 380 * in so it can be fixed later. 381 */ 382 383 struct jbd2_journal_handle 384 { 385 /* Which compound transaction is this update a part of? */ 386 transaction_t *h_transaction; 387 388 /* Number of remaining buffers we are allowed to dirty: */ 389 int h_buffer_credits; 390 391 /* Reference count on this handle */ 392 int h_ref; 393 394 /* Field for caller's use to track errors through large fs */ 395 /* operations */ 396 int h_err; 397 398 /* Flags [no locking] */ 399 unsigned int h_sync: 1; /* sync-on-close */ 400 unsigned int h_jdata: 1; /* force data journaling */ 401 unsigned int h_aborted: 1; /* fatal error on handle */ 402 unsigned int h_type: 8; /* for handle statistics */ 403 unsigned int h_line_no: 16; /* for handle statistics */ 404 405 unsigned long h_start_jiffies; 406 unsigned int h_requested_credits; 407 408 #ifdef CONFIG_DEBUG_LOCK_ALLOC 409 struct lockdep_map h_lockdep_map; 410 #endif 411 }; 412 413 414 /* 415 * Some stats for checkpoint phase 416 */ 417 struct transaction_chp_stats_s { 418 unsigned long cs_chp_time; 419 __u32 cs_forced_to_close; 420 __u32 cs_written; 421 __u32 cs_dropped; 422 }; 423 424 /* The transaction_t type is the guts of the journaling mechanism. It 425 * tracks a compound transaction through its various states: 426 * 427 * RUNNING: accepting new updates 428 * LOCKED: Updates still running but we don't accept new ones 429 * RUNDOWN: Updates are tidying up but have finished requesting 430 * new buffers to modify (state not used for now) 431 * FLUSH: All updates complete, but we are still writing to disk 432 * COMMIT: All data on disk, writing commit record 433 * FINISHED: We still have to keep the transaction for checkpointing. 434 * 435 * The transaction keeps track of all of the buffers modified by a 436 * running transaction, and all of the buffers committed but not yet 437 * flushed to home for finished transactions. 438 */ 439 440 /* 441 * Lock ranking: 442 * 443 * j_list_lock 444 * ->jbd_lock_bh_journal_head() (This is "innermost") 445 * 446 * j_state_lock 447 * ->jbd_lock_bh_state() 448 * 449 * jbd_lock_bh_state() 450 * ->j_list_lock 451 * 452 * j_state_lock 453 * ->t_handle_lock 454 * 455 * j_state_lock 456 * ->j_list_lock (journal_unmap_buffer) 457 * 458 */ 459 460 struct transaction_s 461 { 462 /* Pointer to the journal for this transaction. [no locking] */ 463 journal_t *t_journal; 464 465 /* Sequence number for this transaction [no locking] */ 466 tid_t t_tid; 467 468 /* 469 * Transaction's current state 470 * [no locking - only kjournald2 alters this] 471 * [j_list_lock] guards transition of a transaction into T_FINISHED 472 * state and subsequent call of __jbd2_journal_drop_transaction() 473 * FIXME: needs barriers 474 * KLUDGE: [use j_state_lock] 475 */ 476 enum { 477 T_RUNNING, 478 T_LOCKED, 479 T_FLUSH, 480 T_COMMIT, 481 T_COMMIT_DFLUSH, 482 T_COMMIT_JFLUSH, 483 T_FINISHED 484 } t_state; 485 486 /* 487 * Where in the log does this transaction's commit start? [no locking] 488 */ 489 unsigned long t_log_start; 490 491 /* Number of buffers on the t_buffers list [j_list_lock] */ 492 int t_nr_buffers; 493 494 /* 495 * Doubly-linked circular list of all buffers reserved but not yet 496 * modified by this transaction [j_list_lock] 497 */ 498 struct journal_head *t_reserved_list; 499 500 /* 501 * Doubly-linked circular list of all metadata buffers owned by this 502 * transaction [j_list_lock] 503 */ 504 struct journal_head *t_buffers; 505 506 /* 507 * Doubly-linked circular list of all forget buffers (superseded 508 * buffers which we can un-checkpoint once this transaction commits) 509 * [j_list_lock] 510 */ 511 struct journal_head *t_forget; 512 513 /* 514 * Doubly-linked circular list of all buffers still to be flushed before 515 * this transaction can be checkpointed. [j_list_lock] 516 */ 517 struct journal_head *t_checkpoint_list; 518 519 /* 520 * Doubly-linked circular list of all buffers submitted for IO while 521 * checkpointing. [j_list_lock] 522 */ 523 struct journal_head *t_checkpoint_io_list; 524 525 /* 526 * Doubly-linked circular list of temporary buffers currently undergoing 527 * IO in the log [j_list_lock] 528 */ 529 struct journal_head *t_iobuf_list; 530 531 /* 532 * Doubly-linked circular list of metadata buffers being shadowed by log 533 * IO. The IO buffers on the iobuf list and the shadow buffers on this 534 * list match each other one for one at all times. [j_list_lock] 535 */ 536 struct journal_head *t_shadow_list; 537 538 /* 539 * Doubly-linked circular list of control buffers being written to the 540 * log. [j_list_lock] 541 */ 542 struct journal_head *t_log_list; 543 544 /* 545 * List of inodes whose data we've modified in data=ordered mode. 546 * [j_list_lock] 547 */ 548 struct list_head t_inode_list; 549 550 /* 551 * Protects info related to handles 552 */ 553 spinlock_t t_handle_lock; 554 555 /* 556 * Longest time some handle had to wait for running transaction 557 */ 558 unsigned long t_max_wait; 559 560 /* 561 * When transaction started 562 */ 563 unsigned long t_start; 564 565 /* 566 * When commit was requested 567 */ 568 unsigned long t_requested; 569 570 /* 571 * Checkpointing stats [j_checkpoint_sem] 572 */ 573 struct transaction_chp_stats_s t_chp_stats; 574 575 /* 576 * Number of outstanding updates running on this transaction 577 * [t_handle_lock] 578 */ 579 atomic_t t_updates; 580 581 /* 582 * Number of buffers reserved for use by all handles in this transaction 583 * handle but not yet modified. [t_handle_lock] 584 */ 585 atomic_t t_outstanding_credits; 586 587 /* 588 * Forward and backward links for the circular list of all transactions 589 * awaiting checkpoint. [j_list_lock] 590 */ 591 transaction_t *t_cpnext, *t_cpprev; 592 593 /* 594 * When will the transaction expire (become due for commit), in jiffies? 595 * [no locking] 596 */ 597 unsigned long t_expires; 598 599 /* 600 * When this transaction started, in nanoseconds [no locking] 601 */ 602 ktime_t t_start_time; 603 604 /* 605 * How many handles used this transaction? [t_handle_lock] 606 */ 607 atomic_t t_handle_count; 608 609 /* 610 * This transaction is being forced and some process is 611 * waiting for it to finish. 612 */ 613 unsigned int t_synchronous_commit:1; 614 615 /* Disk flush needs to be sent to fs partition [no locking] */ 616 int t_need_data_flush; 617 618 /* 619 * For use by the filesystem to store fs-specific data 620 * structures associated with the transaction 621 */ 622 struct list_head t_private_list; 623 }; 624 625 struct transaction_run_stats_s { 626 unsigned long rs_wait; 627 unsigned long rs_request_delay; 628 unsigned long rs_running; 629 unsigned long rs_locked; 630 unsigned long rs_flushing; 631 unsigned long rs_logging; 632 633 __u32 rs_handle_count; 634 __u32 rs_blocks; 635 __u32 rs_blocks_logged; 636 }; 637 638 struct transaction_stats_s { 639 unsigned long ts_tid; 640 unsigned long ts_requested; 641 struct transaction_run_stats_s run; 642 }; 643 644 static inline unsigned long 645 jbd2_time_diff(unsigned long start, unsigned long end) 646 { 647 if (end >= start) 648 return end - start; 649 650 return end + (MAX_JIFFY_OFFSET - start); 651 } 652 653 #define JBD2_NR_BATCH 64 654 655 /** 656 * struct journal_s - The journal_s type is the concrete type associated with 657 * journal_t. 658 * @j_flags: General journaling state flags 659 * @j_errno: Is there an outstanding uncleared error on the journal (from a 660 * prior abort)? 661 * @j_sb_buffer: First part of superblock buffer 662 * @j_superblock: Second part of superblock buffer 663 * @j_format_version: Version of the superblock format 664 * @j_state_lock: Protect the various scalars in the journal 665 * @j_barrier_count: Number of processes waiting to create a barrier lock 666 * @j_barrier: The barrier lock itself 667 * @j_running_transaction: The current running transaction.. 668 * @j_committing_transaction: the transaction we are pushing to disk 669 * @j_checkpoint_transactions: a linked circular list of all transactions 670 * waiting for checkpointing 671 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 672 * to start committing, or for a barrier lock to be released 673 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 674 * @j_wait_done_commit: Wait queue for waiting for commit to complete 675 * @j_wait_checkpoint: Wait queue to trigger checkpointing 676 * @j_wait_commit: Wait queue to trigger commit 677 * @j_wait_updates: Wait queue to wait for updates to complete 678 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 679 * @j_head: Journal head - identifies the first unused block in the journal 680 * @j_tail: Journal tail - identifies the oldest still-used block in the 681 * journal. 682 * @j_free: Journal free - how many free blocks are there in the journal? 683 * @j_first: The block number of the first usable block 684 * @j_last: The block number one beyond the last usable block 685 * @j_dev: Device where we store the journal 686 * @j_blocksize: blocksize for the location where we store the journal. 687 * @j_blk_offset: starting block offset for into the device where we store the 688 * journal 689 * @j_fs_dev: Device which holds the client fs. For internal journal this will 690 * be equal to j_dev 691 * @j_maxlen: Total maximum capacity of the journal region on disk. 692 * @j_list_lock: Protects the buffer lists and internal buffer state. 693 * @j_inode: Optional inode where we store the journal. If present, all journal 694 * block numbers are mapped into this inode via bmap(). 695 * @j_tail_sequence: Sequence number of the oldest transaction in the log 696 * @j_transaction_sequence: Sequence number of the next transaction to grant 697 * @j_commit_sequence: Sequence number of the most recently committed 698 * transaction 699 * @j_commit_request: Sequence number of the most recent transaction wanting 700 * commit 701 * @j_uuid: Uuid of client object. 702 * @j_task: Pointer to the current commit thread for this journal 703 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 704 * single compound commit transaction 705 * @j_commit_interval: What is the maximum transaction lifetime before we begin 706 * a commit? 707 * @j_commit_timer: The timer used to wakeup the commit thread 708 * @j_revoke_lock: Protect the revoke table 709 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 710 * current transaction. 711 * @j_revoke_table: alternate revoke tables for j_revoke 712 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 713 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 714 * number that will fit in j_blocksize 715 * @j_last_sync_writer: most recent pid which did a synchronous write 716 * @j_history: Buffer storing the transactions statistics history 717 * @j_history_max: Maximum number of transactions in the statistics history 718 * @j_history_cur: Current number of transactions in the statistics history 719 * @j_history_lock: Protect the transactions statistics history 720 * @j_proc_entry: procfs entry for the jbd statistics directory 721 * @j_stats: Overall statistics 722 * @j_private: An opaque pointer to fs-private information. 723 */ 724 725 struct journal_s 726 { 727 /* General journaling state flags [j_state_lock] */ 728 unsigned long j_flags; 729 730 /* 731 * Is there an outstanding uncleared error on the journal (from a prior 732 * abort)? [j_state_lock] 733 */ 734 int j_errno; 735 736 /* The superblock buffer */ 737 struct buffer_head *j_sb_buffer; 738 journal_superblock_t *j_superblock; 739 740 /* Version of the superblock format */ 741 int j_format_version; 742 743 /* 744 * Protect the various scalars in the journal 745 */ 746 rwlock_t j_state_lock; 747 748 /* 749 * Number of processes waiting to create a barrier lock [j_state_lock] 750 */ 751 int j_barrier_count; 752 753 /* The barrier lock itself */ 754 struct mutex j_barrier; 755 756 /* 757 * Transactions: The current running transaction... 758 * [j_state_lock] [caller holding open handle] 759 */ 760 transaction_t *j_running_transaction; 761 762 /* 763 * the transaction we are pushing to disk 764 * [j_state_lock] [caller holding open handle] 765 */ 766 transaction_t *j_committing_transaction; 767 768 /* 769 * ... and a linked circular list of all transactions waiting for 770 * checkpointing. [j_list_lock] 771 */ 772 transaction_t *j_checkpoint_transactions; 773 774 /* 775 * Wait queue for waiting for a locked transaction to start committing, 776 * or for a barrier lock to be released 777 */ 778 wait_queue_head_t j_wait_transaction_locked; 779 780 /* Wait queue for waiting for checkpointing to complete */ 781 wait_queue_head_t j_wait_logspace; 782 783 /* Wait queue for waiting for commit to complete */ 784 wait_queue_head_t j_wait_done_commit; 785 786 /* Wait queue to trigger checkpointing */ 787 wait_queue_head_t j_wait_checkpoint; 788 789 /* Wait queue to trigger commit */ 790 wait_queue_head_t j_wait_commit; 791 792 /* Wait queue to wait for updates to complete */ 793 wait_queue_head_t j_wait_updates; 794 795 /* Semaphore for locking against concurrent checkpoints */ 796 struct mutex j_checkpoint_mutex; 797 798 /* 799 * List of buffer heads used by the checkpoint routine. This 800 * was moved from jbd2_log_do_checkpoint() to reduce stack 801 * usage. Access to this array is controlled by the 802 * j_checkpoint_mutex. [j_checkpoint_mutex] 803 */ 804 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH]; 805 806 /* 807 * Journal head: identifies the first unused block in the journal. 808 * [j_state_lock] 809 */ 810 unsigned long j_head; 811 812 /* 813 * Journal tail: identifies the oldest still-used block in the journal. 814 * [j_state_lock] 815 */ 816 unsigned long j_tail; 817 818 /* 819 * Journal free: how many free blocks are there in the journal? 820 * [j_state_lock] 821 */ 822 unsigned long j_free; 823 824 /* 825 * Journal start and end: the block numbers of the first usable block 826 * and one beyond the last usable block in the journal. [j_state_lock] 827 */ 828 unsigned long j_first; 829 unsigned long j_last; 830 831 /* 832 * Device, blocksize and starting block offset for the location where we 833 * store the journal. 834 */ 835 struct block_device *j_dev; 836 int j_blocksize; 837 unsigned long long j_blk_offset; 838 char j_devname[BDEVNAME_SIZE+24]; 839 840 /* 841 * Device which holds the client fs. For internal journal this will be 842 * equal to j_dev. 843 */ 844 struct block_device *j_fs_dev; 845 846 /* Total maximum capacity of the journal region on disk. */ 847 unsigned int j_maxlen; 848 849 /* 850 * Protects the buffer lists and internal buffer state. 851 */ 852 spinlock_t j_list_lock; 853 854 /* Optional inode where we store the journal. If present, all */ 855 /* journal block numbers are mapped into this inode via */ 856 /* bmap(). */ 857 struct inode *j_inode; 858 859 /* 860 * Sequence number of the oldest transaction in the log [j_state_lock] 861 */ 862 tid_t j_tail_sequence; 863 864 /* 865 * Sequence number of the next transaction to grant [j_state_lock] 866 */ 867 tid_t j_transaction_sequence; 868 869 /* 870 * Sequence number of the most recently committed transaction 871 * [j_state_lock]. 872 */ 873 tid_t j_commit_sequence; 874 875 /* 876 * Sequence number of the most recent transaction wanting commit 877 * [j_state_lock] 878 */ 879 tid_t j_commit_request; 880 881 /* 882 * Journal uuid: identifies the object (filesystem, LVM volume etc) 883 * backed by this journal. This will eventually be replaced by an array 884 * of uuids, allowing us to index multiple devices within a single 885 * journal and to perform atomic updates across them. 886 */ 887 __u8 j_uuid[16]; 888 889 /* Pointer to the current commit thread for this journal */ 890 struct task_struct *j_task; 891 892 /* 893 * Maximum number of metadata buffers to allow in a single compound 894 * commit transaction 895 */ 896 int j_max_transaction_buffers; 897 898 /* 899 * What is the maximum transaction lifetime before we begin a commit? 900 */ 901 unsigned long j_commit_interval; 902 903 /* The timer used to wakeup the commit thread: */ 904 struct timer_list j_commit_timer; 905 906 /* 907 * The revoke table: maintains the list of revoked blocks in the 908 * current transaction. [j_revoke_lock] 909 */ 910 spinlock_t j_revoke_lock; 911 struct jbd2_revoke_table_s *j_revoke; 912 struct jbd2_revoke_table_s *j_revoke_table[2]; 913 914 /* 915 * array of bhs for jbd2_journal_commit_transaction 916 */ 917 struct buffer_head **j_wbuf; 918 int j_wbufsize; 919 920 /* 921 * this is the pid of hte last person to run a synchronous operation 922 * through the journal 923 */ 924 pid_t j_last_sync_writer; 925 926 /* 927 * the average amount of time in nanoseconds it takes to commit a 928 * transaction to disk. [j_state_lock] 929 */ 930 u64 j_average_commit_time; 931 932 /* 933 * minimum and maximum times that we should wait for 934 * additional filesystem operations to get batched into a 935 * synchronous handle in microseconds 936 */ 937 u32 j_min_batch_time; 938 u32 j_max_batch_time; 939 940 /* This function is called when a transaction is closed */ 941 void (*j_commit_callback)(journal_t *, 942 transaction_t *); 943 944 /* 945 * Journal statistics 946 */ 947 spinlock_t j_history_lock; 948 struct proc_dir_entry *j_proc_entry; 949 struct transaction_stats_s j_stats; 950 951 /* Failed journal commit ID */ 952 unsigned int j_failed_commit; 953 954 /* 955 * An opaque pointer to fs-private information. ext3 puts its 956 * superblock pointer here 957 */ 958 void *j_private; 959 960 /* Reference to checksum algorithm driver via cryptoapi */ 961 struct crypto_shash *j_chksum_driver; 962 963 /* Precomputed journal UUID checksum for seeding other checksums */ 964 __u32 j_csum_seed; 965 }; 966 967 /* 968 * Journal flag definitions 969 */ 970 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 971 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 972 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 973 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 974 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 975 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 976 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 977 * data write error in ordered 978 * mode */ 979 980 /* 981 * Function declarations for the journaling transaction and buffer 982 * management 983 */ 984 985 /* Filing buffers */ 986 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 987 extern void __jbd2_journal_refile_buffer(struct journal_head *); 988 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 989 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 990 extern void __journal_free_buffer(struct journal_head *bh); 991 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 992 extern void __journal_clean_data_list(transaction_t *transaction); 993 994 /* Log buffer allocation */ 995 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 996 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 997 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 998 unsigned long *block); 999 void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1000 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1001 1002 /* Commit management */ 1003 extern void jbd2_journal_commit_transaction(journal_t *); 1004 1005 /* Checkpoint list management */ 1006 int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 1007 int __jbd2_journal_remove_checkpoint(struct journal_head *); 1008 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 1009 1010 1011 /* 1012 * Triggers 1013 */ 1014 1015 struct jbd2_buffer_trigger_type { 1016 /* 1017 * Fired a the moment data to write to the journal are known to be 1018 * stable - so either at the moment b_frozen_data is created or just 1019 * before a buffer is written to the journal. mapped_data is a mapped 1020 * buffer that is the frozen data for commit. 1021 */ 1022 void (*t_frozen)(struct jbd2_buffer_trigger_type *type, 1023 struct buffer_head *bh, void *mapped_data, 1024 size_t size); 1025 1026 /* 1027 * Fired during journal abort for dirty buffers that will not be 1028 * committed. 1029 */ 1030 void (*t_abort)(struct jbd2_buffer_trigger_type *type, 1031 struct buffer_head *bh); 1032 }; 1033 1034 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh, 1035 void *mapped_data, 1036 struct jbd2_buffer_trigger_type *triggers); 1037 extern void jbd2_buffer_abort_trigger(struct journal_head *jh, 1038 struct jbd2_buffer_trigger_type *triggers); 1039 1040 /* Buffer IO */ 1041 extern int 1042 jbd2_journal_write_metadata_buffer(transaction_t *transaction, 1043 struct journal_head *jh_in, 1044 struct journal_head **jh_out, 1045 unsigned long long blocknr); 1046 1047 /* Transaction locking */ 1048 extern void __wait_on_journal (journal_t *); 1049 1050 /* Transaction cache support */ 1051 extern void jbd2_journal_destroy_transaction_cache(void); 1052 extern int jbd2_journal_init_transaction_cache(void); 1053 extern void jbd2_journal_free_transaction(transaction_t *); 1054 1055 /* 1056 * Journal locking. 1057 * 1058 * We need to lock the journal during transaction state changes so that nobody 1059 * ever tries to take a handle on the running transaction while we are in the 1060 * middle of moving it to the commit phase. j_state_lock does this. 1061 * 1062 * Note that the locking is completely interrupt unsafe. We never touch 1063 * journal structures from interrupts. 1064 */ 1065 1066 static inline handle_t *journal_current_handle(void) 1067 { 1068 return current->journal_info; 1069 } 1070 1071 /* The journaling code user interface: 1072 * 1073 * Create and destroy handles 1074 * Register buffer modifications against the current transaction. 1075 */ 1076 1077 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 1078 extern handle_t *jbd2__journal_start(journal_t *, int nblocks, gfp_t gfp_mask, 1079 unsigned int type, unsigned int line_no); 1080 extern int jbd2_journal_restart(handle_t *, int nblocks); 1081 extern int jbd2__journal_restart(handle_t *, int nblocks, gfp_t gfp_mask); 1082 extern int jbd2_journal_extend (handle_t *, int nblocks); 1083 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 1084 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 1085 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 1086 void jbd2_journal_set_triggers(struct buffer_head *, 1087 struct jbd2_buffer_trigger_type *type); 1088 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 1089 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 1090 extern void journal_sync_buffer (struct buffer_head *); 1091 extern int jbd2_journal_invalidatepage(journal_t *, 1092 struct page *, unsigned long); 1093 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 1094 extern int jbd2_journal_stop(handle_t *); 1095 extern int jbd2_journal_flush (journal_t *); 1096 extern void jbd2_journal_lock_updates (journal_t *); 1097 extern void jbd2_journal_unlock_updates (journal_t *); 1098 1099 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1100 struct block_device *fs_dev, 1101 unsigned long long start, int len, int bsize); 1102 extern journal_t * jbd2_journal_init_inode (struct inode *); 1103 extern int jbd2_journal_update_format (journal_t *); 1104 extern int jbd2_journal_check_used_features 1105 (journal_t *, unsigned long, unsigned long, unsigned long); 1106 extern int jbd2_journal_check_available_features 1107 (journal_t *, unsigned long, unsigned long, unsigned long); 1108 extern int jbd2_journal_set_features 1109 (journal_t *, unsigned long, unsigned long, unsigned long); 1110 extern void jbd2_journal_clear_features 1111 (journal_t *, unsigned long, unsigned long, unsigned long); 1112 extern int jbd2_journal_load (journal_t *journal); 1113 extern int jbd2_journal_destroy (journal_t *); 1114 extern int jbd2_journal_recover (journal_t *journal); 1115 extern int jbd2_journal_wipe (journal_t *, int); 1116 extern int jbd2_journal_skip_recovery (journal_t *); 1117 extern void jbd2_journal_update_sb_errno(journal_t *); 1118 extern void jbd2_journal_update_sb_log_tail (journal_t *, tid_t, 1119 unsigned long, int); 1120 extern void __jbd2_journal_abort_hard (journal_t *); 1121 extern void jbd2_journal_abort (journal_t *, int); 1122 extern int jbd2_journal_errno (journal_t *); 1123 extern void jbd2_journal_ack_err (journal_t *); 1124 extern int jbd2_journal_clear_err (journal_t *); 1125 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 1126 extern int jbd2_journal_force_commit(journal_t *); 1127 extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode); 1128 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, 1129 struct jbd2_inode *inode, loff_t new_size); 1130 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); 1131 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); 1132 1133 /* 1134 * journal_head management 1135 */ 1136 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 1137 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 1138 void jbd2_journal_put_journal_head(struct journal_head *jh); 1139 1140 /* 1141 * handle management 1142 */ 1143 extern struct kmem_cache *jbd2_handle_cache; 1144 1145 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 1146 { 1147 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); 1148 } 1149 1150 static inline void jbd2_free_handle(handle_t *handle) 1151 { 1152 kmem_cache_free(jbd2_handle_cache, handle); 1153 } 1154 1155 /* 1156 * jbd2_inode management (optional, for those file systems that want to use 1157 * dynamically allocated jbd2_inode structures) 1158 */ 1159 extern struct kmem_cache *jbd2_inode_cache; 1160 1161 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags) 1162 { 1163 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags); 1164 } 1165 1166 static inline void jbd2_free_inode(struct jbd2_inode *jinode) 1167 { 1168 kmem_cache_free(jbd2_inode_cache, jinode); 1169 } 1170 1171 /* Primary revoke support */ 1172 #define JOURNAL_REVOKE_DEFAULT_HASH 256 1173 extern int jbd2_journal_init_revoke(journal_t *, int); 1174 extern void jbd2_journal_destroy_revoke_caches(void); 1175 extern int jbd2_journal_init_revoke_caches(void); 1176 1177 extern void jbd2_journal_destroy_revoke(journal_t *); 1178 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 1179 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 1180 extern void jbd2_journal_write_revoke_records(journal_t *, 1181 transaction_t *, int); 1182 1183 /* Recovery revoke support */ 1184 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 1185 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 1186 extern void jbd2_journal_clear_revoke(journal_t *); 1187 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 1188 extern void jbd2_clear_buffer_revoked_flags(journal_t *journal); 1189 1190 /* 1191 * The log thread user interface: 1192 * 1193 * Request space in the current transaction, and force transaction commit 1194 * transitions on demand. 1195 */ 1196 1197 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 1198 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 1199 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1200 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1201 int jbd2_journal_force_commit_nested(journal_t *journal); 1202 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1203 int jbd2_log_do_checkpoint(journal_t *journal); 1204 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 1205 1206 void __jbd2_log_wait_for_space(journal_t *journal); 1207 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1208 extern int jbd2_cleanup_journal_tail(journal_t *); 1209 1210 /* Debugging code only: */ 1211 1212 #define jbd_ENOSYS() \ 1213 do { \ 1214 printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \ 1215 current->state = TASK_UNINTERRUPTIBLE; \ 1216 schedule(); \ 1217 } while (1) 1218 1219 /* 1220 * is_journal_abort 1221 * 1222 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1223 * bit, when set, indicates that we have had a fatal error somewhere, 1224 * either inside the journaling layer or indicated to us by the client 1225 * (eg. ext3), and that we and should not commit any further 1226 * transactions. 1227 */ 1228 1229 static inline int is_journal_aborted(journal_t *journal) 1230 { 1231 return journal->j_flags & JBD2_ABORT; 1232 } 1233 1234 static inline int is_handle_aborted(handle_t *handle) 1235 { 1236 if (handle->h_aborted) 1237 return 1; 1238 return is_journal_aborted(handle->h_transaction->t_journal); 1239 } 1240 1241 static inline void jbd2_journal_abort_handle(handle_t *handle) 1242 { 1243 handle->h_aborted = 1; 1244 } 1245 1246 #endif /* __KERNEL__ */ 1247 1248 /* Comparison functions for transaction IDs: perform comparisons using 1249 * modulo arithmetic so that they work over sequence number wraps. */ 1250 1251 static inline int tid_gt(tid_t x, tid_t y) 1252 { 1253 int difference = (x - y); 1254 return (difference > 0); 1255 } 1256 1257 static inline int tid_geq(tid_t x, tid_t y) 1258 { 1259 int difference = (x - y); 1260 return (difference >= 0); 1261 } 1262 1263 extern int jbd2_journal_blocks_per_page(struct inode *inode); 1264 extern size_t journal_tag_bytes(journal_t *journal); 1265 1266 /* 1267 * Return the minimum number of blocks which must be free in the journal 1268 * before a new transaction may be started. Must be called under j_state_lock. 1269 */ 1270 static inline int jbd_space_needed(journal_t *journal) 1271 { 1272 int nblocks = journal->j_max_transaction_buffers; 1273 if (journal->j_committing_transaction) 1274 nblocks += atomic_read(&journal->j_committing_transaction-> 1275 t_outstanding_credits); 1276 return nblocks; 1277 } 1278 1279 /* 1280 * Definitions which augment the buffer_head layer 1281 */ 1282 1283 /* journaling buffer types */ 1284 #define BJ_None 0 /* Not journaled */ 1285 #define BJ_Metadata 1 /* Normal journaled metadata */ 1286 #define BJ_Forget 2 /* Buffer superseded by this transaction */ 1287 #define BJ_IO 3 /* Buffer is for temporary IO use */ 1288 #define BJ_Shadow 4 /* Buffer contents being shadowed to the log */ 1289 #define BJ_LogCtl 5 /* Buffer contains log descriptors */ 1290 #define BJ_Reserved 6 /* Buffer is reserved for access by journal */ 1291 #define BJ_Types 7 1292 1293 extern int jbd_blocks_per_page(struct inode *inode); 1294 1295 /* JBD uses a CRC32 checksum */ 1296 #define JBD_MAX_CHECKSUM_SIZE 4 1297 1298 static inline u32 jbd2_chksum(journal_t *journal, u32 crc, 1299 const void *address, unsigned int length) 1300 { 1301 struct { 1302 struct shash_desc shash; 1303 char ctx[JBD_MAX_CHECKSUM_SIZE]; 1304 } desc; 1305 int err; 1306 1307 BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) > 1308 JBD_MAX_CHECKSUM_SIZE); 1309 1310 desc.shash.tfm = journal->j_chksum_driver; 1311 desc.shash.flags = 0; 1312 *(u32 *)desc.ctx = crc; 1313 1314 err = crypto_shash_update(&desc.shash, address, length); 1315 BUG_ON(err); 1316 1317 return *(u32 *)desc.ctx; 1318 } 1319 1320 #ifdef __KERNEL__ 1321 1322 #define buffer_trace_init(bh) do {} while (0) 1323 #define print_buffer_fields(bh) do {} while (0) 1324 #define print_buffer_trace(bh) do {} while (0) 1325 #define BUFFER_TRACE(bh, info) do {} while (0) 1326 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1327 #define JBUFFER_TRACE(jh, info) do {} while (0) 1328 1329 #endif /* __KERNEL__ */ 1330 1331 #endif /* _LINUX_JBD2_H */ 1332